An asylum seeker on Manus Island says he has been raped twice in detention in the past four months, but fears going to the police because he has been told he will be jailed for being homosexual.

Mohammad* has reported the assaults to camp security, but lives in fear of further attacks: months after being raped – on two separate occasions by two different men – the man is still living in the same compound as his alleged attackers.

Other gay asylum seekers in the detention centre say they are regularly sexually harassed and assaulted, and have contemplated suicide if they are forced to live in the PNG community.

In an interview from detention, Mohammad told Guardian Australia he is regularly sexually assaulted by fellow detainees, but is too scared to report the attacks because homosexuality is illegal in Papua New Guinea and he has been told by camp authorities he will be jailed.

Mohammad fled Iran after facing persecution because of his sexuality. In Iran, homosexuality is punishable by death. He has been in detention on Manus Island for more than a year.

“I had to get out of Iran and … I came to Australia, a country that says that it supports human rights … but unfortunately the Australian government brought me to a place where I’m still in danger.”

Mohammad said he lives every day in fear of being attacked again.

“Most of the toilets here don’t have locks. When someone is in the toilets or bathrooms, they easily get inside. It’s happened for me sometimes that when I’m showering, guys … who have overflowing sexual desires, come inside. I’ve been able to kick them out sometimes but sometimes not.”

On two occasions, Mohammad said, he had been overpowered and raped.

“It has happened to me twice, and happened as I [just] told you.”

Mohammad said gay men on Manus are targeted by men who are “sexually and psychologically under pressure”.

“Here in this camp, about 1,200 people … all are single and all are male … these people are [sexually] thirsty. So when they identify the gay people here, they approach them and do … this molestation.”

Mohammad said he had reported the incidents to Wilson Security, which manages the camp, but fears going to PNG authorities.

“I didn’t want this incident to be reported [to the police] because of being afraid of the police and what if they find out [that I am gay] and arrest me. I [could be] jailed for 14 years.”

Mohammad said he was told by immigration department staff he should not tell anyone about the threats made against him, and said he was not allowed to speak to the media.

“But we don’t have anything to defend ourselves with. Our only way to defend ourselves is to talk to the media and speak out.”

Another gay man, Abbas*, told Guardian Australia he had been sexually harassed and threatened with rape regularly since arriving on Manus in August 2013. He said he was too scared to shower because of constant threats, and had asked to be moved to a new compound away from his tormentors, but is still waiting to be transferred. He said he would refuse to be resettled in PNG, where he could be arrested and jailed for his homosexuality.

“I will stay in camp as much as I can. If they want to send me out, I will end my life.”

Guardian Australia has been told that there are approximately 50 gay asylum seekers among the 1,056 single male detainees on Manus Island.

Redacted letter from ‘Farhad’: Detention is a ‘nightmare’.Photograph: Supplied

Previously, four gay asylum seekers have written letters, obtained by Guardian Australia, detailing assaults by fellow detainees and by guards, and of their own attempts to commit suicide. Another letter received this week said gay refugees were frightened by their imminent resettlement in PNG.

Farhad* said his detention was a “nightmare”, but that he also feared being released into the PNG community because he believed he would be attacked by locals and jailed.

“Committing suicide is the only thing I can think of. I want to kill myself because, on the one hand, it is impossible for me to go back to Iran, and on the other hand, I am not able to tolerate this situation anymore,” he wrote.

When detainees arrived on Manus Island, they were given a briefing by the Salvation Army that showed a picture of two men kissing with a large red cross through it.

The delivery notes attached to the presentation warned: “Homosexuality is illegal in Papua New Guinea. People have been imprisoned or killed for performing homosexual acts”.

Guardian Australia reporters have been refused access to Manus Island detention centre, but spoke with seven workers who are currently working or had recently worked on the Manus detention centre.

None can speak publicly about the situation on Manus because of government-imposed confidentiality clauses, which threaten legal prosecution and possible imprisonment for breaches. But all seven independently confirmed that rape and sexual assaults were common in the detention centre.

“Everyone knows what goes on, rape happens regularly, but no one does anything about it,” one said.

The workers spoke about an aggressive and hostile environment inside the centre, where physically stronger detainees bullied, threatened and attacked smaller ones. Detainees report they sleep during the daytime because it is too dangerous to sleep at night.

“It is a prison, and the place operates like a prison, there is a lot of aggression. The strong prey on the weak,” another Manus worker said.

Young men are particularly vulnerable, Guardian Australia was told. At least one man has presented to medical staff on Manus complaining of a bleeding penis, a suspected sexually-transmitted infection. One worker on the island was told one Burmese asylum seeker was another detainee’s “bitch”.

“Manus is a prison and prisons have a hierarchy of power. The weak need protection from the strong, so this Burmese man is a strong man’s ‘bitch’ for protection.”

“I witnessed a very young Myanmar [Burmese] man enter a toilet to be followed by another Myanmar client,” she said in a submission to the inquiry. “The particular transferee who alerted me to this behaviour informed that the young Myanmar transferee regularly went inside this toilet with different men on a daily basis.

“Upon seeing this I informed a male G4S guard at the Oscar guardhouse what was currently occurring inside the toilet block. The G4S guard said that the transferees are homosexuals, and if I had a problem to file an incident report.

“I saw the young Myanmar transferee walk out of the toilet block looking to be in pain.”

Judge said the since-closed P Block in Foxtrot compound was known as a “rape dungeon”, while fellow Salvation Army worker Christopher Iacono said it was known as “a hotspot for sexual activities”.

G4S guard Martin Appleby told the same inquiry he had had to deal with a sexual assault victim in Foxtrot compound.

Inquiries from Wilson Security were referred to Transfield, then on to the immigration department. The department has not responded to requests for comment.